Power unit



Dec. 16, 1947. R. s. WILLIAMS 2,432,705

POWER UNIT Filed May 30, 1944 INVEN TOR.

A441 ATTORNEY Patented Dec. 16, 1947 UNITED STATES PATENT OFFICE POWERUNIT Ray "S. Williams, Orrville, Ohio, assignor to John M. Hopwood,Mount Lebanon, Pa.

This invention relates to diaphragm power units operative in response tovarying pressures of a loading line having a relatively short stroke foruse as valve regulators.

It is among the objects of the invention to provide a diaphragm powerunit in which the reaction of balancing pressure on the loading pressureis cancelled out without the use of stufling boxes or bellows seals andthe like.

Another object of the invention is theprovlsion of a diaphragm typevalve regulator which is extremely sensitive in its operation inresponse to slight variations of the loading pressure.

These and other objects of the invention will become more apparent froma consideration of the accompanying drawing constituting a part hereofin which Fig. 1 is a cross-sectional view taken centrally of a diaphragmpower unit; and Fig. 2 a cross-section of an enlarged detail of a valveof said unit, which comprises a housing having flanges 2 and 3 to whichare attached sectional members 4, 5, and 6 at one end and I and 6 at theother end, secured by through bolts 9 and I respectively. A cap II isprovided with a threaded opening l2 for receiving a valve I3, shown inthe enlarged view, Fig. 2, controlling the application of a source ofconstant pressure indicated by the arrow, valve |3 having a valve stemi4 biased by a coil spring Hi to the closed position, and which whenopen directs the flow of the constant fluid pressure from the source tothe chamber designated by the numeral i6. Chamber I6 is connected by aconduit I I to chamber |8 so that the pressures in chambers l6 and i8are always equal.

Numeral l9 designates a lever fulcrumed at for regulating a valvedesignated by the numeral 2|. Lever I9 is actuated by the diaphragmoperator which it abuts at 22 and which has a relatively short strokelimited by the capacity for movement of its connecting diaphragms. Theoperator comprises a bolt secured by a nut 23 to a collar 24 whichcoacts with a flanged collar 25 to clamp a diaphragm 26 therebetween,the flange of the collar 25 also engaging a diaphragm 2! which isclamped to a nut 28 in which bolt 22 is threaded. Nut 28 is providedwith a shoulder 29 for seating a coil spring 30, one end of whichengages a spring seat 3| disposed around a nut 32 threaded into bolt 33,which is provided with a flange 34 having a valve seat 35 thatconstitutes the mouth of a vent passage 36 leading to the vent 31between diaphragms 38 and 39 that are secured by a collar 40 and acollar 4|. A diaphragm 38' is provided as a flexible seal for bolt orrod 33 where it projects into chamber l8. An operating diaphragm 42 isdisposed between the collar 4| and a collar 43, all of which are clampedby the nut 32 on the valve bolt 33. The space between diaphragms 39 and42 forms a part of a chamber 44. Chamber 44 has a threaded connection 45with a conduit leading to a source of loading pressure. The spacebetween diaphragms 26 and 21 forms part of a chamber 46. Chamber 46 hasan opening 41 to which a source of supply of constant line pressure (notshown) may be connected. As may be seen by inspection of Fig. 1,diaphragms 38, 39, 38', and 26 are shown as being of the same size, andthat diaphragms 21 and 42 are substantially equal in size. It will alsobe observed that since diaphragms 38 and 38' are of the same size andalways subjected to the same value of pressure, the forces developed bythe pressure acting on them will be equal and opposite. Since diaphragm42 is larger than diaphragm 39, the effective net area of these twodiaphragms from the standpoint of the pressure in chamber 44 acting 'onthem is the difference between the effective areas of the largerdiaphragm 42 and the smaller diaphragm 39. The net force developed bythe pressure in chamber 44 and acting on diaphragms 39 and 42 will bethe product of the pressure and the efiective net areas thereof, and theforce developed will act towards the right, that is towards spring 36.Likewise, the net force developed by the pressure in chamber 46 actingon diaphragms 26 and 21, will be the product of the pressure and thedifference between the effective areas of the larger and smallerdiaphragms 21 and 26. This force will act towards the left or towardsspring 36. The force required to actuate lever i9 is the force developedby the pressure in chamber i8 acting on the effective area of diaphragm21 minus the net opposing force developed by the pressure in chamber 46acting on diaphragms 21 and 26.

It will also be observed by inspection of Fig. 1 that the vent 36 andthe inlet port of valve i3 will be closed when the net operating forcedeveloped by the pressure in chamber 44 on diaphragms 39 and 42 is inbalance with the opposing force exerted by spring 30.

The operation of the diaphragm operator is as follows: With a constantline pressure in chamber 46 tending to compress spring 30, the valveseat 35 is urged against the end of the valve stem l4, closing vent 36and maintaining equal pressures in chambers I6 and I8 which balances thepressure on the diaphragmil and prevents vent the latter, causingdiaphragm 21 to act against spring to restore valve seat to the positionof contact with valve stem i4, thereby closing vent 38. Movement of theoperator to the vent closing position will depress valve stem I4 andopen valve l3 to admit the constant pressure fluid into chamber 16 whichthrough the loading conduit i1 is transmitted to chamber l8, therebyrestoring the diaphragm operator to its normal position, in whichposition valve stem I4 is again seated in the vent opening 35 and theair supply valve i3 is closed.

Since there are no packing glands for the moving parts of the diaphragmoperator there is no friction and the device is extremely sensitive toslight variations between pressures in the loading line and the constantline pressure in line 41, rendering the device instantly responsive toany pressure changes, and restoring balance without lag. Such a deviceis especially adapted for sensitive regulation of fuel or air controlvalves for furnaces and the like.

Although one embodiment of the invention has been illustrated anddescribed, it will be evident to those skilled in the art that variousmodifications may be made in the details of construction withoutdeparting from the principles herein set forth.

I claim;

1. A diaphragm power unit comprising a sectional housing having acentral chamber, an operator disposed in said chamber having a pluralityof diaphragms extending radially to the wall of said chamber, dividingthe same into a plurality of pressure chambers, a source of constantpressure fluid for the end chambers, a source of variable loadingpressure for an intermediate chamber, a loading conduit connecting oneof the end chambers with another intermedi-- ate chamber, a valveoperable in response to movement of said operator for venting saidconduit-connected chambers and for supplying pressure fluid to saidchambers to balance out prising a plurality of threaded rods having aresilient connection therebetween and having a plurality of diaphragmsmounted thereon and secured to the inner wall of said housing, dividingthe housing into a plurality of pressure chambers, a source of constantpressure fluid for the end chambers. a source of variable loadingpressure for an intermediate chamber, a loading conduit connecting oneof the end chambers with another intermediate chamber, a valve operablein response, to movement of said operator for venting saidconduit-connected chambers and for supplying pressure fluid to saidchambers to balance out the pressure in the other of said end chambers.

3. A diaphragm power unit comprising a sectional housing having acentral chamber, a jointed operator disposed in said chamber comprisinga plurality of threaded rods having a resilient connection therebetweenand having a plurality of diaphragms mounted thereon and secured to theinner wall of said housing, dividing the housing into a plurality ofpressure chambers, one of said rods having a passage at one end forventing the end pressure chamber, a valve controlling said vent passagehaving connection with a source of constant pressure and being normallybiased to close said vent passage, a loading conduit connecting said endchamber with a chamber intermediate said rods, a source of constantpressure for the other of said end chambers and a source of variableloading pressure for another intermediate chamber for subjecting saidrods to movement against the resistance of the resilient connectiontherebetween, the movement of the rod having the vent passage operatingthe valve in the end chamber to vent said chamber and the intermediatechamber connected by the loading conduit and to open the valve in saidend chamber to admit fluid pressure into said chamber and to saidintermediate chamber to counteract the pressure in the other of said endchambers.

RAY S. WILLIAMS.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS Number Name Date 2,219,062 Almond Oct. 22, 19402,304,782 Donaldson Dec. 15, 1942 2,350,615 Joesting June 6, 1944971,207 Michel Sept. 27, 1910 FOREIGN PATENTS Number Country Date476,341 Great Britain Dec. 11, 1937 544,753 Great Britain Apr. 27, 1942

